Yeah, I know and the strict Christians refused vaccination based on the virgin principle too.

But still the doctors I know would want some explanation about that virginity, and consider oral sex 'sexually active' for example.

Close skin to skin contact of the genital area, it says, and the risk from hand-to-genital transmission is extremely low. How much of a virgin are you if you've had everything but penetration?

Sometimes. If you have an HPV related cervical cancer and claim you're a virgin they're not really going to believe it.

Also, about the smoking: lying about it won't always work because they have noses and you're going to be wanting to take cigarette breaks during your hospital stay. If you quit smoking a while ago you're likely to mention it because quitting is a positive thing.